Duration of synchronous egg cleavage cycles at different temperatures in Siberian sturgeon (Acipenser baerii)

摘要

The duration of synchronous cleavage divisions, equal to the interval between the corresponding mitotic phases of two consecutive cleavage divisions (tau(0)), was determined in Siberian sturgeon (Acipenser baerii Brandt) at different water temperatures. The linear relationship between tau(0) (in minutes) and water temperature (T) was logtau(0) = 2.79-0.07 T (r = 0.996; P < 0.001) for temperature interval between 8.3 and 12.0 &DEG;C, while at higher temperatures (13-23.0 &DEG;C) this relationship was logτ(0) = 2.09 - 0.02 T (r = 0.910; P < 0.001). According to tau(0) values, the range of optimal temperatures for early development of Siberian sturgeon eggs was between 12.5 and 20 degreesC. At temperatures exceeding 20 degreesC; tau(0) did not decrease and even exhibited tendency to increase, indicating the upper boundary of optimal temperatures for embryos.